Drawing-table



E. R. KOECHLIN.

DRAWING TABLE.

APPLICATION FILED on. 5. msfi 1,341,988. Patented June 1, 1920.

Attorney.

"UNITED STATES!" EMILE RAYMOND KOECHLIN, or AMSTERDAM,NETHERLANDS,ASSIGNOR T0 NAAMLOOZEVENNOOTSCHAP wsnuw'n J. AHRENTD & zooms INDUSTRIE-EN HANDELSVEREENIGING, or AMSTERDAM, NETHERLANDS, A COMPANY on THENETHERLANDS.

DRAWING-TABLE.

Patented June 1,

Application filed Gctober 5, 1918. Serial No. 257,637.

To all whom it may concern:

Be it known that I, EMILE RAYMOND KonoHLIN, a subject of the Queen oftheNetherlands, residing at Amsterdam, in the Kingdom of the Netherlands,have invented certain new and useful Improvements in Drawing-Tables, ofwhich the following is a specification.

My present invention relates to drawing tables and is more particularlyapplicable to drawing tables of the type comprising a drawing boardconnected with two adjacent joints of an articulated parallelogram guidethe third joint of which forms a fixed fulcrum and is connected with theboard by a link which extends beyond said fulcrum and is provided with acounterweight for counterbalancing the board, whereas the fourth jointis pivoted to a member whose freedom of motion is counteracted by asuitable friction device.

My invention is designed to provide improved means for avoiding anyundue change in the form of the parallelogram guide as long as the boardis normally used, but allowing at the same time the form of said linkmechanism to be changed when desired by a comparatively slight pressureexerted on the board.

My invention will be best understood by reference. to the accompanyingdrawing, which will now be described, it being understood, however, thatvarious changes may be made in the details of construction andarrangement by those skilled in the art, without departing from thespirit and scope of my invention.

In the drawing:

Figure 1 is a side elevation of a drawing table embodying my invention,Fig. 2 being a sectional view on a larger scale of that part of thedrawing table which comprises the 1 Securedto the lever 7 carrying thecoun-' terweight 8 and concentric relative to the fulcrum 2 is acircular rod 9 passing through hole in a sleeve'lO secured to across-piece 11 betweenthe legs 12 and 13 of the table, a cap 14 beingscrewed on said sleeve. Lo-

'cated. within said sleeve is helical spring .15 one end of which bearsagainst the screw cap 14, the other end bearing against a brake shoe 16.Said brake shoe 16, which normally contacts with the circular rod 9, isadapted to press said rod against a second brake shoe 17 I V A screwbolt 18 which is provided with a handle 19 and screwed through the coverof the cap 1%, is adapted to be screwed into the sleeve 10 through asufficient distance to press the brake shoe 16 against the rod 9 even ifthe cap 14: is turned back as far as possible. 7 V

When using my improved drawing table I put the helical spring 15 underproper tension by means of the screw cap 14, whereby the rod 9 isgripped between the brake shoes 16 and 17, and I adjust this grippingforce so that the rod 9 does not tend to slide within the sleeve 10 whenI use the board in the usual manner, that is to say, as long as I amdrawing, and that an increased pressure on the board is required forcausing a displacement of said rod. this gripping force will beinitially adjusted to suit the requirements, but, once adjusted, itshould preferably be left unchanged. The bolt 18 is normally screwedbackso far that its end does not engage the brake shoe 16. v V

The arrangement described evidently prevents the board from being undulydisplaced parallel with itself as long as it is normally used, but it.allows of this movement being effected, if desired, by an increasedpressure exerted on the board.

Now, if I wish to firmly secure the rod 9 within the sleeve 10, forinstance, if at any moment it should be desired to increase the load ofthe board, I turn the screw bolt 18 As a matter of course,

until the frictional resistance of the brake I claim as new and desireto protect by Letters Patent of the United States:

1. In a drawing'table, the combination of v a drawing board,'a support,a pivot on said 2. In a drawing table, the combination of 7 I support, alink connected to said board and to said pivot, a curved rod concentricwith said pivot and secured to saidjlink,'a sleeve secured to saidsupport, saidrod extending through said sleeve, a brake-shoe adapted toengage sald rod, a cap "in threaded -engagement with said sleeve, aspring interposed between said shoe and cap, and a screwspindie inthreaded engagement with said cap and adapted to bear against said shoe.

In testimony whereof I affix mysignature.

EMILE RAYMOND KOEGHIJIN. '5

Vitnesses D. KLIJN, M. ALVARADO.

